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Biomedical subjects

H Oka

Publications and source records attributed to H Oka.

At least 361 records · Page 20Linked to original sources
PubMed1988

Free fatty acids in human pure pancreatic juice.

Human pure pancreatic juice (PPJ) and serum were analyzed for free fatty acids (FFAs) to study whether the damage to pancreatic cell membranes in pancreatitis is reflected as abnormal FFAs concentration and composition. Patients consisted of 13 normal controls, 7 patients with acute pancreatitis (AP) in remission, and 27 with chronic pancreatitis (CP). PPJ was collected at 2-min intervals after secretin and then cholecystokininpancreozymin stimulation by endoscopic cannulation of the pancreas. The following results were obtained: (a) serum FFAs concentration and composition showed no significant difference between the three groups. (b) FFAs concentration in PPJ was significantly raised in CP through all secretory phases. The rise was significant only in "secretin phase" in AP. In many of the cases with raised FFAs concentration in PPJ, the FFAs composition was similar to that in serum. (c) Arachidonic acid, undetected in normal PPJ, was disproportionately high in concentration and composition in PPJ of eight patients with CP. Two mechanisms were proposed to explain these abnormalities: transudation of serum FFAs into the pancreatic duct and local production of arachidonic acid as a result of the damage to pancreatic cell membranes.

Acute Disease↗
PubMed1988

Pepsinogens I and II in gastric cancer: an immunohistochemical study using monoclonal antibodies.

Monoclonal antibodies were used to examine the immunohistochemical expression of pepsinogens I and II in 31 early and 76 advanced gastric cancers. Of the 107 carcinomas studied, 19 contained pepsinogen II and only 3, found exclusively in pepsinogen II-positive cases, contained pepsinogen I. Gastric cancer produces pepsinogen II more frequently than pepsinogen I, and production of the latter is significantly associated with the former. Histologically, there were 54 intestinal-type and 53 diffuse-type cancers. The former produced pepsinogen II more frequently than the latter. In the diffuse type, the four pepsinogen II-positive cases were found exclusively in females. Although the pepsinogen expression was independent of the macroscopic features in advanced gastric cancer, it was found that the protruded-type early gastric cancer produced pepsinogen II more frequently than the depressed type. Incidences of pepsinogen positivity were not different between early and advanced gastric cancers or between cancers with or without lymph node metastasis, suggesting that production of pepsinogen is independent of tumor growth.

Aged↗
PubMed1988

Exchange blood transfusion for acute hepatic failure: its limited availability depending on the type of injury in rats.

The efficacy of exchange blood transfusion for acute hepatic failure was evaluated using rats. Rats receiving a dose of carbon tetrachloride died later than 24 h after dosing. When their blood was replaced with blood from normal rats at 24 h, survival time was prolonged, and hepatic protein synthesis was enhanced at 36 h with improved prothrombin time (PT). Those rats surviving 120 h showed better histological grade of recovery from injury after treatment. In contrast, dimethylnitrosamine (DMN)-intoxicated rats showed no such improvement in survival time or PT. In rats given a nonfatal dose of carbon tetrachloride, serum glutamic-pyruvic transaminase values were five times higher than those in rats given DMN despite similar maximal PT. The benefit of exchange transfusion for acute hepatic failure may differ depending on the mechanism of development in rats. Enhanced hepatic protein synthesis may contribute to its effect.

Acute Disease↗
PubMed1988

Intravascular coagulation in acute liver failure in rats and its treatment with antithrombin III.

Liver damage was induced in rats by injection of dimethylnitrosamine (DMN) or carbon tetrachloride (CCl4). Fibrin clots were observed in the hepatic sinusoids at 12 hours and soluble fibrin monomer complexes were markedly detected at 24 hours only in the rats given DMN. When antithrombin III concentrate was infused at 12 hours there was a dose dependent improvement of the values of serum total bilirubin, SGPT, prothrombin time, peripheral platelet count, and plasma fibrinogen and coagulation factor VIIIC and of the histological degree of liver injury at 24 hours in the DMN group. The CCl4-group showed no such improvement. Intravascular coagulation may complicate the course of certain types of acute liver injury and contribute to its aggravation in rats. Under such circumstances, treatment with antithrombin III concentrate would be beneficial.

Animals↗
PubMed1988

Characteristics of acetylcholine-induced phosphorylase a activity in uterine segments as a substitute for contractile response to acetylcholine.

Studies were made on whether the ACh-induced phosphorylase a activity in isolated rat uterine muscle segments could be used as a substitute for the contractile response to ACh. This ACh-induced phosphorylase a activity was dependent upon the concentration of ACh and was inhibited by atropine, suggesting that it was linked to muscarinic ACh receptors. Both extracellular calcium and an increase of the intracellular calcium concentration were needed for its activation by ACh. Ca2+-antagonists such as Co2+, diltiazem, nitrendipine and verapamil inhibited the ACh-induced activity, suggesting that the activation by ACh required the influx of calcium ions into the uterine muscle through Ca2+-antagonist sensitive Ca2+ channels. The IC50 values of CoCl2, diltiazem, nitrendipine and verapamil on the ACh-induced phosphorylase a activity were 3.4 x 10(-3) M, 2.5 x 10(-4) M, 2.5 x 10(-5) M and 1.1 x 10(-4) M, respectively. These values were comparable with the IC50 values of these Ca2+-antagonists on the contractile response of isolated rat uterine muscle segments to 3 x 10(-4) M ACh. The inhibitory effects of Co2+, nitrendipine and verapamil, but not diltiazem, on ACh-induced phosphorylase a activity were attenuated by higher concentrations of CaCl2 (0.36 to 2 mM). These findings suggested that the ACh-induced phosphorylase a activity in isolated rat uterine muscle segments could be used as a substitute for the contractile response to ACh.

Acetylcholine↗
PubMed1988

Effects of synthetic omega-conotoxin on the contractile responses of segments of rat ileum, stomach fundus and uterus and guinea pig taenia coli.

The effect of synthetic omega-conotoxin (omega-CgTX) on the contractile responses of segments of rat ileum, stomach fundus and uterus and guinea pig taenia coli were investigated. Omega-CgTX (10(-9)-5 x 10(-6) M) did not inhibit the contractile responses of all smooth muscle segments to high KCl and/or ACh. However, unexpectedly, omega-CgTX (3 x 10(-7)-10(-5) M) alone caused dose-dependent contraction of segments of the stomach fundus and uterus. These contractile responses to omega-CgTX alone depended upon the presence and/or the influx of extracellular Ca2+; and they were inhibited by calcium antagonists such as diltiazem, nitrendipine and verapamil, with the exception that the segments of stomach fundus was not inhibited by verapamil. With the segments of uterus, but not those of other tissues, omega-CgTX (10(-7)-5 x 10(-6) M) significantly enhanced the contractile responses to various concentrations of ACh and high KCl. With rat ileum and guinea pig taenia coli segments, omega-CgTX (10(-9)-5 x 10(-6) M) did not induce a contractile response or have an enhancing effect. These findings suggest that omega-CgTX may have a calcium agonist-like effect on smooth muscles such as the stomach fundus and uterus of rats.

Acetylcholine↗
PubMed1988

Prevalence of cardiovascular diseases in the Kingdom of Tonga.

The blood pressure, electrocardiographic findings and serum total cholesterol of Tongans, characterized by extreme obesity, were compared with those of Japanese employees of a trading firm in Tokyo. The prevalence of cardiovascular diseases in Tongans as far as assessed by these measurements was rather low for their excessive obesity. It is unclear whether the relatively low prevalence rate of cardiovascular diseases among the Tongans is due to genetic factors which might be considered an ethnological difference, or to environmental factors. Reducing weight is very difficult for many obese people. Accordingly, if "healthy obesity" exists, elucidation of its mechanism will be glad tidings for obese persons. However, the most prevalent diseases among the Tongans were the same as those of the developing countries. Consequently, imitating the Tongan lifestyle does not necessarily assure the longevity of obese persons of developed nations, although it may decrease the risk of the cardiovascular diseases.

Adult↗
PubMed1988

Glucagon and insulin for the treatment of hepatic failure in dimethylnitrosamine-intoxicated rats.

When rats received dimethylnitrosamine every 24 h until death, plus hormone treatment after the first 24 h, the survival was enhanced between 100 and 140 h compared with the control rats, with attenuated derangements of prothrombin time and serum albumin levels at 120 h. In rats given a single dose of dimethylnitrosamine, hepatic DNA synthesis peaked at 48 h. The synthesis was increased after hormone treatment when started immediately, but not when delayed for 24 h. Hormone treatment for 3 days starting 24 h after a single dose of dimethylnitrosamine produced a rapid normalization of decreased hepatic protein content on day 9, although hepatic DNA content was not affected. These results suggest that this treatment is effective for hepatic failure, and the promotion of restoration of liver function is a contributing factor to its effect, in addition to the stimulation of hepatocyte proliferation.

Animals↗
PubMed1988

Evidence for potentiation of lipid peroxidation in the rat liver after chronic ethanol feeding.

Hepatic steatosis was induced in rats by feeding nutritionally adequate liquid diet containing ethanol as 36% of energy for 4-5 weeks. After 24 h fasting and withdrawal from ethanol, liver ischaemia for 30 min followed by 2 h reperfusion resulted in a significant increase in microsomal lipid peroxide content and a decrease in reduced glutathione content as well as in protein synthesis with a rapid accumulation of triglyceride in the liver. In rats fed a non-ethanol diet or those fed a high-cholesterol diet with hepatic steatosis, however, similar phenomena were not found. These findings suggest that chronic ethanol feeding potentiates hepatic lipid peroxidation.

Animals↗
PubMed1988

[Clinical research on transfer of cefpiramide to the blood and large intestinal tissue in patients with cancer of the large bowel].

Cefpiramide (CPM) shows antibacterial activity against Staphylococci, Enterococci, Pseudomonas aeruginosa and anaerobic Bacteroides spp. CPM is a cephalosporin antibiotic which also exhibits antibacterial activity against Klebsiella and intestinal bacteria including Escherichia coli. Concentrations in blood of CPM which has antibacterial activity against main bacterial species detected during gastrointestinal surgeries and concentration transferred to the large intestinal tissue were measured in patients with cancer of the large intestine. Eighteen patients who were hospitalized and underwent large intestinal surgery from December, 1985 to March, 1987 were examined as subjects. CPM was administered at a dose 1 g each of 11 cases and 2 g to each of 7 cases. Concentrations in blood after administration of 1 g of CPM were in a range of 81.56-212.6 micrograms/ml between 25 minutes and 2 hours 20 minutes after administration, and concentrations in the large intestinal tissue were in a 14.17-66.95 micrograms/g range. Ratios of the tissue to the blood concentrations were 0.08-0.49, averaging 0.24 +/- 0.05. Concentrations in blood after administration of 2 g of CPM were 128.4-253.5 micrograms/ml between 1 hour 10 minutes and 3 hours 50 minutes after administration. Tissue concentrations were 48.33-116.5 micrograms/g between 1 hour 10 minutes and 5 hours 15 minutes after administration. Ratios of the tissue to the blood concentrations were 0.21-0.55, averaging 0.42 +/- 0.05 between 1 hour 10 minutes and 3 hours 5 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗